Henry davey



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H. DAVEY. PUMPING ENGINE.

No. 434,704. Patented Aug. 19, 1890.

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HENRY DAVEY, OF WESTMINSTER, ENGLAND.

PUMPING-ENGINE.

SPECIFICATION forming part of Letters Patent No. 434,704, dated August19, 1890.

Application filed January 31, 1890- Serial No. 338,715- (No modal.)

' .To all whom it may concern:

Be it known that I, HENRY DAVEY, a subject of the Queen of GreatBritain, residing at No. 3 Princes Street, WVestminster, in the countyof Middlesex, England, have invented certain new and useful Improvementsin Pumping-Engines; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it app ertains to make and use thesame.

My invention relates to compound pumping-engines; and it consists of animproved construction, hereinafter fully described, and specificallyclaimed, in which a pump, an intermediate compensating frame andmechanism, and a compound expansion steam-engine and valve-gear andmotor thereof, of novel construction, for operating the main valves arecombined, whereby the motion of the engine is so regulated as to produceimproved and more beneficial results under like circumstances during theoperation. I

In the accompanying drawings, Figure 1 is an elevation of my invention;Fig. 2, a plan view of the same; Fig. 3, a longitudinal vertical centralsection of the steam-engine proper; Fig. 4, a vertical central sectionthrough the cylinders of an auxiliary valve-operating engine; Fig. 5, ahorizontal section of the same in the line of its pistons; Fig. 6, aside elevation; Fig. 7, an end elevation of the same; and Fig. 8 is anenlarged detail View of two coupled cut-off valves of the mainsteam-cylinder.

The letters A A in the drawings represent the pump-barrels; (7.6L, theirpiston-rods; a at, their connecting-rods; B, an oscillating intermediatecompensating frame; 0 C, steamcylinders; 0, their common piston-rodg c',connecting-rod, and D valve-gear-operating engine.

The compensating frame B consists of two parallel disks B, fastened to ashaft N, which latter is hung to the main frame of the ma chine. Thesaid disks are provided with crank pins b b b, of which I) I) operateconnecting-rods a a of two pumps A A, and b is operated by theconnecting-rod c of the steam-engine. When the crank-pin 1) stands Thewrist-pins b of the connecting-rods of the pumps A A and the wrist-pinsb of the connecting-rod of the compound steam-engine 0* are so arrangedas to increase the lifting-power of the pump A* toward the end of thelifting-stroke. These pins 1) b are fastened to two parallel disks B,having a fulcrum-shaft Z2 hung to a suitable frame X.

The steam-cylinders O O are coupled, andtheir pistons 0 c are fastenedto the piston rod 0, which is provided with a cross-head c and theconnecting-rod c. The steamways c o of cylinder 0 are provided withconical plug-valves E E, which cut off or open communication withsteamways c c c c 0 0 leading to and ending in the valve-seat 0 insideof the steam-chest C The valves E E are ground into their seats in thesteamcylinder 0, and are provided with ports 6 e 6 8 respectively. Attheir small ends they are provided with levers e e respectively, whichare coupled to a rod 6 and a connecting-rod e. The connecting-rod e ispivoted to a lever c on a rock-shaft E suitably hung to the frame X.This rock-shaft E receives its motion by means of a lever E andconnecting-rod e from an. eccentric-pin e on a disk E fastened to themain rock-shaft 12 Thus the motions of the valves E E coincide with themotions of the steam-engine. Thus by the operation of these valves thestroke of the steam-piston is positively determined by cutting offwhatever steam may be admitted through either one of the passages c or 0at the end of the backward or forward stroke. Such steam is therebyconfined in said steam- Ways and economized for the next stroke, and

so confined it also serves as an elastic cush-.

ion, partly balancing the main valve of the engine.

Upon the valve-seat o the main valve F is placed, which is an ordinaryslide-valve with lower and upper ports f f and f 3 f and an exhaust portf. The top surface of the main valve serves as a valve-seat f for anexpansion or cut-01f valve Gr of ordinary construction. The valve Gconsists of two forked heads 9 9, having cut-off flanges g 9 whichlatter slide upon the valve-seat f of the valve F, and are held at aproper distance apart upon the-valve-rod G by means of the forked-headsg g, through which the valverod passes, and also by collars g on thevalverod and nuts g screwed to the valve-rod. The main valve F isfastened by means of clamp-nuts f to its valve-stem F, which is passedthrough said valve.

The cylinder 0 is provided with a steamchest 0 containing a main valveH, having steam-ports h k ]L3 H, exhaust-port 7L5, an upper valve-seatha, and a cut-off valve 1, consisting of two forked heads 2' t withcut-off flanges 6 1' The fastening of said two valves to theirrespective valve-stems II and I is effected in a manner similar to thatof cylinder 0, viz: The valve His fastened by means of two clamp-nutshand the valve Iby means 'of collars i and nuts 1?. The valve-stems Fand H and those G and I are coupled between the valve-chests C C by thewellknown device or devices, as shown, or by some other suitable deviceor devices, and while the cut-off valvesG and I are operated from therock-shaft E by means of a leverarm 9 and connecting-rod g, as seen inFigs. 1 and 2, the valves F and G are operated by a rock-shaft F bymeans of a lever-arm f and connecting-rod f The rock-shaft F is suitablyhung in the frame X and provided with a lever-arm f", which latter isconnected by means of a couple of links j to the main piston-rod J of apiston 7' in a steam-cylinder J of the subsidary engine D. Thissteam-cylinder, which may be operated by water-pressure from thepumpmain or by steam from the boiler, is of ordinary construction, andthe valve-rod j of its slide or main valve 9' is extended out and beyondthe steam space or way d, and is there provided with two collars 7,which serve as abutments of a tappet K on a piston-rod K of a piston ina small steam-cylinder K of ordinary construction. The valve-rod k ofits slide-valve k is connected by means ofa link 10 to a lever L,suitably hung or fulcrumed to an upper frame J of the subsidiary engineD, and this lever is by means of a number of connecting-rods Z Z Z andlevers Z Z or other suitable devices connected to a lever-arm c upon therock-shaft E The main-valve rod j is, above the frame J provided with amortised head j", into which the end in of ahand-lever M is passed, sothat the valve f can be operated by hand in case of an emergency.

Steam is admitted to the valve-chest C of the cylinder 0 from a boilerthrough a pipeconstructed and operated without these lin in "s.

l vhile the piston-rod c is finishing its stroke the pin e", with itsdescribed connections, re-

verses the position of the valve 70, whereby the position of the piston70 and that of the tappet K are reversed. By means of this operation thetappet K reverses the position of the valve j whereby the position ofthe piston j and piston-rod J is reversed, and consequently the mainvalves F H are also reversed. By this construction the said main valvesare always operated with a full-stroke, and the fresh steam from theboiler enters the cylinder 0 through afully-opened port. The stroke ofthe piston-rod c is now limited to its exact extent by the operation ofthe valves G I E F, as will be seen. The exact or correct length of thestroke of the piston-rod 0 can only be attained by the cut-off valves GI and E F, for the reason that they are directly operated from therock-shaft b and thus move simultaneously with the pistonrod 0. Thuswhen the piston-rod c has arrived at the terminus of the stroke thevalve G has previously cut off the steam-supply from the valve F, andthe opposite valve E or E, as the case may be, has cut off the exhaust,so that the piston c is arrested between two elastic cushions of steam,in which position it remains while the subsidiary engine is reversingthe main valves.

It is found that steampumps provided with independent valve-motion, asherein described and shown, cannot be operated with a uniform stroke,and various provisions have been made to avoid unduly prolonged strokes,but at great expense. I therefore provide the main cylinder with anexpansion slidevalve operated by the valve-gear-operating engine D,whereby the end portion of the stroke of the main engine is effectedwith simply expanding steam, thus retarding its speed and greatlyreducing the momentum of the engine, and enabling me by closing thesteam-passage of the main cylinder by the valves E to stop the motionsof the steampistons with greater precision than would be the case if themain cylinder were operated by live steam to the end of the stroke.

What I claim as my invention is 1. The combination of the pump Aintermediate compensating beam B, and operating steam-engine 0*,comprising cylinders O C, a subsidiary valve-motor D for operating themain valves of the steam-engine, and the IIt.

directly-operated cut-off Valves GI E E, sub- In testimony whereof Ihereunto aifix my stantially as described. signatiire in presence of twoWitnesses.

2. The combination of the compound pumping steam-engine 0*, comprisingcylinders O HENRY DAVEY 5 O, piston-rod a, piston c 0 valves E E, F G,Witnesses:

and H I, with the subsidiary engine D, sub- ALEXR. CECIL RIDGWAY,stantially as described. W. N.RIDGWAY.'

